1. Field of the Invention
The present invention relates to orthopaedic instrumentation, and, more particularly, relates to orthopaedic instrumentation which may be used in conjunction with a prosthesis having an offset prosthetic stem extension.
2. Description of the Related Art
It is known to provide a tibial prosthetic implant having a stem extension which is essentially centrally located relative to a base portion. However, a stem which is centrally located on the base portion may interfere with the tibial cortex as the surgeon attempts to center the tibial plate on the proximal cut tibia. Further, the intramedullary (IM) canal of the tibia may not be centrally located relative to the peripheral edges of the proximal tibia. A tibial prosthetic implant having a stem extension which is centrally located relative to a base portion may therefore not allow a proper positioning of the base portion relative to the proximal end of the tibia.
It is also known to provide a tibial prosthesis having a stem extension which is offset relative to a base portion. For example, U.S. Pat. No. 5,290,313 (Heldreth), which is assigned to the assignee of the present invention and incorporated herein by reference, discloses a tibial prosthesis having a stem extension defining a longitudinal axis thereof. The stem extension also includes a stem mounting portion which is disposed offset from the longitudinal axis, such that the longitudinal axis of the stem extension is disposed offset from the location at which the stem extension attaches to the base portion. Utilizing such a tibial prosthesis, the attachment point of the base portion is offset from the IM canal of the tibia. It is therefore possible to more accurately position the base portion of the tibial prosthesis relative to the proximal end of the tibia.
What is needed in the art is an instrumentation assembly which relatively easily prepares the proximal end of the tibia for proper positioning of a tibial prosthesis including a base portion and an offset stem extension.